Bjerrum, Niels

Bjerrum, Niels J. Selected Papers. Copenhagen E. Munksgaard, 1949. 

Amphoteric — a substance that can act both as an acid and a base - acid-base theories, subentry - base-antibase concept, -r ampholyte, - Bjerrum, Niels Jan-niksen, - capillary isoelectric focusing (CIEF), -+ metals. 

Scholz F (2011) Bjerrum, Niels. In Bard AJ, Inzelt G, Scholz F (eds) Electrochemical dictionary. Springer, Berlin... 

Bohr, like all the other individuals mentioned in this chapter, was not a chemist. His only real contact with chemistry came as an undergraduate at the University of Copenhagen. His chemistry teacher, Niels Bjerrum, who later became his close friend and sailing companion, recalled that Bohr set a record for broken glassware that lasted half a century. 

The first ideas concerning a role of pairwise electrostatic interaction between ions were advanced in 1924 by Vladimir K. Semenchenko. A quantitative theory of the formation of ion pairs was formulated in 1926 by Niels Bjerrum. 

On Bjerrum, see Assmus, "Molecular Structure," 5465, 6873 and Assmus, "The Molecular Tradition," esp. 217231. Niels Bjerrum, "On the Infrared Spectra of Gases. III. The Configuration of the Carbon Dioxide Molecule and the Laws of Intramolecular Forces" (1914), 4255, in N. Bjerrum, Selected Papers (Copenhagen ... 

Niels Bjerrum (1879-1958) was a Danish physical chemist who made fundamental contributions to inorganic coordination chemistry and is responsible for much of our understanding of acids and bases and titration curves.5... 

It was shown many years ago by Niels Bjerrum that the ratios of successive acid dissociation constants could be accounted for in a nearly quantitative way by electrostatic considerations. Consider any bifunctional add HXH ... 

Andreas Peter Vestbp, Jens Oluf Jensen, Niels J. Bjerrum, Development of a high-pressure microbalance for hydrogen storage materials, J. All. Compds. 446-447 (2007) 703-706... 

A particularly important question involves the understanding of the role of crystal defects in the peculiar electrical behaviour of ice 4. Upon the application of an electric field, the solid becomes polarized by the thermally activated reorientation of the molecular dipoles. Niels Bjerrum postulated the existence of orientational defects, which represent local disruptions of the hydrogen-bond network of ice 4, to explain the microscopic origin of this phenomenon. 

Let me insert a personal footnote here. These electrostatic effects were first discussed in the chemical literature by Niels Bjerrum (5) in 1923, and in 1938 John Kirkwood and I developed a crude model for such electrostatic systems, and worked out an approximate mathematical theory to put these effects on a quantitative base.f 6,7,8 ... 

Various explanations have been given for deviations from the Debye-Hiickel-Onsager equations. A common type of behavior is for the negative slopes of the A versus /c plots to be greater than predicted by the equation that is, the experimental conductivities are lower than predicted by the theory. This has been explained in terms of ion pairing, a concept which was developed by the Danish physical chemist Niels Bjerrum (1879-1958) in 1926. Although most salts, such as sodium chloride, are present in the solid state and in solution as ions and not as covalent species, there is a tendency for them to come together from time to time to form ion pairs. 

Niels Bjerrum (Copenhagen ii March 1879-30 September 1958), a pupil of Julius Thomsen and later of Nernst, was professor in the Royal Veterinary and Agricultural College, Copenhagen (1914). ... 

NIELS BJERRUM for doing the experimental wak described here. The research reported has been made possible through the support of the U.S.Department of Army under Contract Number DA-91-591-EUC-3153. 

In 1923, a theory for acids and bases was developed by two Danish chanists, Johannes Br0nsted and Niels Bjerrum, and independently by the English chanist Martin Lowry. The chemical equilibrium between adds and bases is given by... 

There is no doubt that Jannik Bjerrum obtained much inspiration from the kinetic and equilibrium studies of his father Niels Bjerrum (1879-1958), the physical chemist (6) best known for his work on chromium(III) complexes. Jannik obtained a comparable success, studying octahedral cobalt(III) conplexes of the N and NgO type (later extended to N O but not beyond S.M.Jj rgensen s type N-O prepared via [(0 NO)2Co(NH2)2] crystals). Jannik s great innovation of using activated charcoal as a catalyst for cobalt (III) equilibria also showed its intrinsic limitations by inducing... 

These results are iirportant for the spectra of inner-sphere complexes with a number of aqua and anionic ligands, whereas I submit respectfully that the arguments about definite activity coefficients (62) are rather circular. Jannik s last publications may illustrate the pragmatic fact that spectra in the visible region are much more uniquely characteristic for the first coordination spheg, as Niels Bjerrum told Werner in 1909 for cases like [ClCr(0H2)c] compared... 

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